Heat-balance duplex-drive.



D. K. DEAN.

HEAT BALANCE DUPLEX DRIVE.

APPLICATION FILED JAN-25,1917. RENEWED MAR. 19.1918.

Patented May 28,1918.

H l/VVE/VTOR 0% 4 /,C Q aid 4% ATTORNEY UNITED STATES. PATENT OFFICE.

DION K. DEAN, OF 'WINTHROP, MASSACHUSETTS, ASSIGNOR TO ALBERGER PUMP ANDCONDENSER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

HEAT-BALANCE DUPLEX-DRIVE.

Specificationof Letters Patent.

Patented May 28, 1918.

Application filed January 25, 1917, Serial No. 144,375. Renewed March19, 1918. Serial No. 228,468.

To all whom it may concern:

Be it known that I, DION K. DEAN,a citizen of the United States, andresident of Winthrop, in the county of Suffolk and State ofMassachusetts, have invented certain new and useful Improvements inHeat- Balance Duplex-Drives, of which the following is a specification,reference being had therein to the accompanying drawing.

This invention relates to a heat balance duplex drive. In the operationof certain kinds of steam power plants, the maximum plant economy with agiven set of apparatus is securedwhen certain machines, such as theordinary plant auxiliaries, are driven by steam, providing that theamount of such steam when passing from the machines in the form ofexhaust steam does not exceed that which is required in the plant forproper use in heating feed water or performing other heating work.

Among many objects which might be mentioned as the object of theinvention, I indicate that my invention will improve the operation ofsteam turbine driven machines in a three-fold way; first: toautomatically supply an amount of driving steam, which when exhaustedwill be proper and adequate to perform the further useful purposes ofsuch exhaust steam; second: to automati cally guard against supplying anamount of driving steam, which when exhausted would be in excess of therequirements for such exhaust steam; and third: to provide fOr thedriven machine a duplex drive from two sources of power, so that in theevent of the failure of one of these power sources, the other willautomatically assume the proper operation of the machine.

In case the power requirements of the plant auxiliaries at any giventime should demand more steam than when exhausted would properly takecare of the stated heating or other requirements for the use of suchexhaust steam, it would be more economical to carry a portion of theauxiliary load by means of an electric motor,which receives its currentfrom the main unit, so as to reduce the quantity of exhaust steam tothat required for the further useful purposesof such exhaust steam,inasmuch as such a drive would give the auxiliaries the benefit ofapproximately the steam rate of the main unit for that portion of theload carried by the electric motor. Since it results that a maximum ofeconomy and safety cannot possibly be secured by manual operation,automatic control is rendered extremely advantageous. It is to berecognized moreover that the accidental stoppage of any of the machinesof the power plant involves serious consequences, and hence, anauxiliary source of power which is instantly available and isautomatically brought into action is made very desirable. The invention,therefore, may be said to consist essentially in the heat balance drivecapable of automatically securing the results mentioned, and in variousdetails and peculiarities in the combination, construction, andarrangement of the various parts, substantially as will be hereinafterdescribed and then more particularly pointed out in the claims.

In the accompanying drawing illustrating my invention:

Figure 1 is a side elevation of a power plant arrangement, includingtherewith the features of my improved heat balance duplex drive.

Fig. 2 is a right hand end elevation of the same.

Fig. 3 is'an enlarged sectional detail of the pressure and the speedgovernor mechanism.

Similar characters of reference designate corresponding parts throughoutthe different figures of the drawing.

1 denotes a driven machine, which may be any kind of a machine, such forexample, as a power plant auxiliary mechanism, a pump, or any other kindof machinery. 2 denotes an electric motor, and 3 a steam turbine, bothof which are connected by suitable shafting and flexible couplings orother means with the driven machine 1 so that either the electric motoror the steam turbine may drive said machine, or either one may vdrivethe rotor of the other in case the other is not in operation. While inthe arrangement illustrated in the drawings the shafts of the machines1, 2 and 3 are directly connected together, it is obvious that they maybe geared or otherwise connected so as to rotate in unison; further, itwill be noted that it is sometimes pos sible that the speed of the"driven machine would not be suitable for direct connection to theturbine or the motor, in which case the shaft of the machine and theshaft of either or both of the other elements might easily be connectedthrough a set of speed reduction gears whereby the required resultswould be efi'ectively obtained. It will be uhderstood that the rotor ofone element will drive the idle rotor of the other element, for if oneend of the shaft, which for operative purposes may be considered assolidly connected to the other end of the shaft,

v is driven, for example, by the motor rotor at one end of the shaftwhile steam is not being admitted to the turbine rotor, the worknecessary to drive that turbine rotor must necessarily be done by themotor rotor; or as the rotors of all the elements may be viewed as partof the shaft, those rotors are driven which do not receive someimpelling force of energy such as electric current in the case of anelectric motor, and steam in the case of a turbine, and that rotor isthe driver which does receive for the time being the outside impellingsource of energy. Obviously there may be some cases where two elementscould be drivers simultaneously, but it is unnecessary to enlarge uponthese features.

The electric motor 2 is properly, located and arranged and connectedelectrically with a suitable source of electric energy so as to operatetherefrom; while steam is admitted to the steam turbine 3- through asteam supply line 4. The exhaust steam from the steam turbine 3 is ledaway through the exhaust line or conduit 5. The admission of the steamto the turbine through the line 4 is controlled in the first instance bya pressure governor which operates a valve 6 situated at a suitablepoint in the length of the pipe 4, as-shown. T will now explain onespecific example of a pressure governor which may be used for thepurpose l have in view, although 1 do not wish to be confined to thisform of pressure governor as it is an example merely and a great manyother kinds may be substituted in lieu of the same for doing the samework. In Figs. 1 and 3 the valve 6 is seen to be carried by a stem 7running upwardly through guides at 8, and being attached to a diaphragm9 which forms one side of a pressure chamber 10, said chamber beingsupported on any suitable frame Work 11. A spring 12 is tensionedbetween the guide 8 and the diaphragm 9 and serves to normally lift thevalve 6 ofi' its seat so that the passageway through the pipe 4 will benormally open. The exhaust pipe 5 moreover connects by pipes 13 and 14with the pressure chamber 10, so that the pressure until when thepressure rises high enough valve 6 Will be closed upon its seat and thepassage of steam to the turbine 3 through line 4 will be cut ofi so longas the valve 6 remains closed. llt will be seen, however, thatordinarily the valve 6 is open and the same pressure will exist inchamber 10 that exists in the exhaust line 5. The tension of the spring12 is so set that until a certain predetermined pressure in the exhaustline. 5 is reached, this overning mechanism,

as already stated, Wil keep valve 6 Wide open, but when a certain higherpressure is reached, valve 6 will be closed tightly and the valve willoccupy intermediate positions with intermediate pressures. The

higher pressure at which the valve 6 is tightly closed by this pressuregovernor would correspond to the maximum desirable or preferred pressureof the exhaust steam for the heating or any other system in which theexhaust steam is utilized, such as would be determined by a pressurerelief valve on this system or other equivalent means for determiningpressure.

According to the mode of operation, therefore, of a pressure governorcombined and related to the steam supply line and the steam exhaust lineof a steam turbine, it will be understood that the amount of steam whichis permitted to pass the valve6 by the action of the pressure governorwill bear a definite relation to the pressure in the exhaust line 5,which latter pressure in its turn is dependent upon the requirements forexhaust steam in the heating or other system in which the exhaust steamis utilized.

To regulatethe speed of the driven rnachine 1 and to guard againstoverspeed, a speed governor is provided, which may be of any type, asfor example, a centrifugal ball governor 15, which I have illustrated.This is driven by being connected with a worm 16 on'the main shaft 16through a pinion 17 on a shaft 18 and beveled gears 19 and 20, thelatter being loose on a vertical valve stem 21 which is supported in afram 32 fixed upon the supply pipe 4, said stem21 being attached to thevalve 22 operating in connection with seat 23 in the pipe 4. The

21 ample liberty to move up and down through it. If the speed of thedriven machine 1 falls below that desired, then the centripetal actionof the balls 24 will serve to open the valve 22 more widely so as toadmit to the turbine 3 a greater quantity of the steam that is permittedto pass the pressure governor by reason of the pressure in the exhaustline 5; and conversely whenever the speed of the machine tends to exceeda proper predetermined speed, the action of the balls in flyingoutwardly will close the valve 22, or move it. closer to or seat ittightly upon its seat 23 and thus decrease or shut off the supply of thesteam which is passing to the turbine through the supply line 4 underthe regulation of the pressure governor.

When the supply of steam admitted to operate the turbine 3=becomesinsufficient to carry the load at the predetermined operat ing speed byreason of the action of the pressure governor, the electric motor willof necessity and in an automatic manner take up the load in an effort tomaintain the proper operating speed for the driven machine, and thus aduplex drive is provided.

In order to guard against a shut-down of the power plant auxiliaries dueto a failure of the supply of electricity or to some injury to themotor, as may occasionally happen, at a time when the pressure from theexhaust line 5 is sufficiently high to cause the pressure governor tohave its valve 6 tightly closed upon its seat so that no steam is beingsupplied to the steam turbine for the time being, I provide a relief orcut-off valve 28 of any suitable type or variety and of sufficient areaOr capacity for the purpose, the same beingpreferably connected to thejunction of the communicating pipes 13 and 14 between the exhaust line 5and the pressure chamber 10 of the pressure governor. so that by theopening of said relief valve 28 which takes place automatically, thepressure which closes the valve 6 of the pressure governor is released,and said valt'e 6 opens and reestahlishes the supply of operating steamto the turbine, leaving said supply to be regulated for the time beingby the action of the speed governor only.

Said relief or cutofi valve 28 is operated by means of a suitablemechanism acted upon by the speed governor at a time when the speed ofthe machine shall have dropped to a predetermined point, and as stated,the action of said valve 28 will cause the pressure in the chamber 10 todrop to that of the atmosphere so that the tension of the opening spring12 will open the valve and allow steam to freely pass through the pipe4:, except in so far as its passage is controlled by the action of thespeed governor.

In the drawings I have illustrated a simple form of operating mechanismwhereby the speed governor controls the opening of the relief valve 28,but it will be understood that I do not wish to be restricted theretoand have shown the same here simply by way of example in order todisclose a practical and successfully operative combination. Abell-crank lever 29 is pivoted at 30 on a bracket 31 carried by theframe of the turbine engine 3, one arm of said bell crank 29 lying inthe vertical path of movement of the rising and falling traveler 27 ofthe ball governor 15, while the other arm of bell-crank 29 is in theform of a catch or latch at 33. The bell-crank 29 is provided with anadjustable screw or block device 34, the lower end of which is below thehorizontal arm of bell-crank 29 and in a position to be struck by thetraveler 27. By adjusting the screw or block 34 up or down it can beregulated so that the action of the bell crank when struck by thetraveler will be properly timed. The catch 33 of bell-crank 29 normallyengages a similar catch 35 forming part of a bell-crank 36 pivoted at 37on the bracket 31, said bell-crank 36 having a weighted arm 40 whichconnects by means of a chain 38 with the operating lever 39 of therelief valve 28. It will be perceived that normally the engagement ofthe catch devices 33 and 35 will hold the bell-cranks in the positionshown in Fig. 1, Where the weighted arm 40 is restrained from fallingand pulling upon the chain 38 so as to open the relief valve 28, butwhen the bell-crank 29 is lifted by the action of the speed governor,and the catch'33 is set free from the catch 35 the weighted arm 40 willoperate to open the relief valve 28.

If the speed of the unit drops, therefore, from any cause to apredetermined point, the traveler 27 of the speed governor 15 will riseto such a point as to engage the lower end of the adjustable screw orblock 34, rotate the bell-crank 29 far enough to disengage the catchdevices 33 and 35, and permit the unbalanced weighted arm 40 to rotatethe latter around its pivot 37 and open the relief valve 28 through theconnection 38. As I have said, it is obvious that the adjustment of thedevice 31 will allow the traveler 27 to engage the same at any speeddesired. Although I have shown this particular mechanism for operatingthe relief valve, yet it is only one of many which might be used, and itwill be understood that the mechanism may be of any type suitable forthe purpose.

A desirable feature. and one which I find can be used effectively, is asmall steam pipe 50 having therein by-pass valve 51, which would permita sufficient amount of steam to flow past the two valves to keep theturbine casing at a proper temperature for instant operation. The amountof steam passing through this by-pass valve 51 would be very small,being insuflicient to operate the turbine proper, and only enough tokeep the temperature practically constant, but it might be an essentialfeature of the operation, and l, therefore, describe it here as makingfor the best practice.

It will thus be seen that T have provided a heat balance duplex drivefor pumps and other machinery which is very efiective and useful andwhich can easily attain the objects which I have in view. When theconditions arise, as stated, the members of the duplex drive are broughtinto operation, also, the serious results of any accidental stoppage areavoided, and there is an economy in the consumption and use of thesteam, so thatin fact the whole combination is productive of useful andvaluable results.

lln order to more fully explain the operation, I will illustrate byconcrete example of how the load is balanced between the two elements.Suppose that the driven machine is a centrifugal pump with an allowableoperating speed of between 1760 and 1800 R. P. M. The motor will be aninduction motor connected to a 60 cycle circuit, and will have a no-loadoperating speed of 1800 it. P. M. The turbine speed governor will be setso that when the pressure governor is wide open and the turbine iscarrying a full maximum load, namely, running the machine and the idlerotor of the motor, this turbine will run the machine at a speed of 1800R. P. M.

Let us suppose that it is desired to use the exhaust steam in a feedwater heating system under a pressure which does not exceed 3 pounds persquare inch gage. This pressure could be kc t from exceeding this amountby means 0 a relief valve on the feed water heater or some other part ofthe system. The tension device on the pressure governor will be set sothat the pressure governor valve will be completely closed when thepressure in the exhaust line rises to 3 pounds per square inch gage, butthis Valve will be wide open when the pressure is only 2 pounds persquare inch gage. We will assume the machine is running in this way andthat because of the fact that for some reason there may be a surplusamount of steam in the feed water heating system, the pressure in thissystem and the turbine exhaust line would rise until it reaches 2 poundsper square inch gage at which time the pressure governor valve starts toclose; as this starts to close the speed of the unit would fall slightlybecause the turbine would not be receiving enough steam to operate theunit at the fullspeed. llt is one of the principles-of operation of aninduction motor that when it is connected to an electric circuit andreceives its excitation from a generator with which it is in synchronismthat if the speed of that motor is slowed down from any cause, such asthe application of some force to the rotor, the motor will convertelectrical energy into mechanical energy in an efi'ort to overcome theforce which has caused it to slow down below the synchronous no-loadoperating speed. Since the reduction of the amount of steam admitted tothe turbine would tend to slow down the whole unit including the motor,this motor will automatically assume part of the load at the speedresultin from the decrease in the steam supply. f the pressure in theexhaust line rises to 3 pounds per square inch gage the pressure overnorvalve will be closed completely an the entire load including thatnecessary to run the turbine rotor will be assumed by the motor. If thepressure in the exhaust line falls below 3 pounds per square inch, steamwill be admitted to the turbine and part of the load will automaticallybe assumed by it.

If the pressure continues to fall, more and more of the load will becarried by the turbine until the pressure drops to 2 pounds per squareinch gage at which point the pressure overnor valve will be wide open.The spee governor will admit all the steam necessary to maintain a speedof 1800 R. P. M., which speed is the no-load synchronous speed of themotor, at which speed it cannot deliver power to the shaft of themachine, or in other words, under this condition the turbine would becarrying the full load.

Many changes may be made in the precise construction, combination, andarrangement of the specific elements in their relation to each other forattaining the objects in view, and T, therefore, reserve the liberty ofmaking all such changes as experience may indicate to be wise andpractical.

Having thus described my invention, what ll claim as new and desire tosecure by Letters Patent is 1. Tn a heat balance duplex drive, the com-'bination of a machine, an electric motor and a steam turbine arranged todrive the machine singly or together, and either operative to drive therotor of the other when the latter is idle, a steam supply for theturbine and an exhaust for the same, and a pressure governor responsiveto the variations of pressure in the exhaust, and a valve for relievingthe pressure at certain times in the pressure governor, together withmeans for operating said relief valve.

2. The combination of a driven machine, a motor for driving it, a steamturbine for likewise driving the machine, means for permitting saidmotor and turbine to operate jointly or singly, and either to drive therotor of the other when the latter is inoperative, a steam supply linefor the turbine, a steam exhaust line for the turbine, a pressuregovernor, means for connecting the exhaust line to the supply line, inwhich means the pressure governor is located so as to be responsive tothe variations of pressure in the exhaust line, and control the admisionof steam to the turbine from the steam supply line, together with arelief valve arranged in connection with the pressure governor forrendering the latter unresponsive at times to variations of pressure inthe steam exhaust line.

3. The combination of a machine, an electric motor and a steam turbineboth arranged to drive the same singly or jointly, and either operativeto drive the rotor of the other when the latter is idle, a steam supplyline to and a steam exhaust line from the turbine, a pressure governorresponsive to the variations of pressure in the exhaust line controllingthe amount of steam admitted through the supply line, a speed governor,and means whereby said governor serves as a secondary control for theadmission of steam through the supply line, to-

gether with a valve for relieving the pressure at certain times in thepressure governor, and means for operating said relief valve. I

4. The combination of a machine, a motor and a turbine for driving thesame jointly or singly, means for supplying steam to the turbine, meansfor exhausting steam therefrom, means for connecting the exhaust and thesupply, a pressure governor arranged in connection with the latter meansand responsive to the variations of pressure in the exhaust for thepurpose of controlling the quantity of steam admitted through thesupply, a speed governor controlling the admission of such steam as ispermitted to pass the pressure governor, said speed governors serving asa secondary control for the admission of steam through the supply line,together with a relief valve arranged in connection with the pressuregovernor for rendering the latter unresponsive at times to variations ofpressure in the steam exhaust line.

5. The combination of a machine, an electric motor and a steam turbine,each serving to drive the machine when operatin singly or when operatingtogether, and eit er 0perative to drive the rotor of the other whenidle, a steam supply line to and a steam exhaust line from the turbine,a pressure governor responsive to the variations of pressure in theexhaust controlling the quantity of steam admitted through thesupply, aspeed governor responsive to the speed of the driven machine and servingas a secondary control for the admission of steam through the sup lyline, and a relief or cutofi valve for re ieving the pressure in thepressure governor and operated by the speed a governor.

6. The combination of a machine, an electrio motor and a steam turbine,each serving to drive the machine when operating singly or whenoperating together, and either operative to drive the rotor of the otherwhen the latter is idle, a steam supply line and a steam exhaust linefrom the turbine, a pressure governor responsive to the variations ofpressure in the exhaust controlling the quantity of steam admittedthrough the supply, a speed governor responsive to the speed of thedriven machine servin as a secondary control for the admission 0 steamthrough the supply line, means for connecting the steam exhaust line andthe pressure governor, a pressure relief valve arran ed in connectionwith said means for ren ering the pressure governor unresponsive tovariations of pressure in the steam exhaust line, and a mechanismactuated by the speed governor when the machine is running at apredetermined speed for operating the pressure relief valve.

7 The combination with a driven element, and motor devices for drivingthe same singly or together, of a steam supply for one of the motors andan exhaust for the same,a pressure governor responsive to the variationsof pressure in the exhaust, and a relief valve for relieving thepressure in the pressure governor, together with means for automaticallyoperating said relief valve.

8. In a heat balance drive, the combination of a driven machine, motorsfor operating the same singly or together and either operative to drivethe rotor of the other when the latter is idle, a steam supply for oneof said motors and an exhaust for the same, a pressure governorresponsive to the variations of pressure in the exhaust, a speedgovernor responsive to the speed of the driven machine and acting as asecondary control for the admission of steam through the supply line,and a valve for relieving the pressure in the pressure governor, saidvalve being operated by the speed governor.

9. The combination of a driven element, motors for actuating the same,each serving to drive the machine when operating singly or together andeither operative to drive the rotor of the other when idle, a steamsupply line and a steam exhaust line for one of said motors, a pressuregovernor connected to the exhaust line and controlling the quantity ofsteam admitted through the supply, a speed governor acting as asecondary control for the admission of steam, and a valve for relievingthe pressure in the pressure governor.

1.0. The combination of a machine, a plurality of means for actuatingthe same, each serving. to drive the machine when 0 eratin singly ortogether, a steam supply ine an a steam exhaust line for-one of saidoperating means, a pressure governor connected with the exhaust, a speedgovernor respone V Leeneee sive to the speed of the driven machine andspeed governor when the machine is running serving as a secondarycontrol for the adat a predetermined speed for operating the mission ofsteam through the supply line, pressure relief valve. 1 means forconnecting the steam exhaust line In testimony whereof I hereunto afixmy 5 and the pressure governor, a pressure relief signature.

valve arranged in connection with said means, and a mechanism actuatedby the DMDN K. DEAN,

